The goal of this application is to build a headgear monitor that will provide a quantitative estimate of headgear use (both time and force) that can be related to treatment effects. Furthermore, this monitor has been designed not only to measure headgear wear but to enhance it. Psychological research suggests that the simple act of monitoring behavior improves patient compliance with therapeutic regimens. Feedback on compliance will be readily available to patients, parents, and the orthodontist and, if desired, the actual data can be downloaded to computer equipment commonly found in orthodontic offices. Improving compliance with headgear wear may have several clinically beneficial consequences. For example, orthodontic corrections may proceed more quickly with a consequent reduction in the adverse side effects associated with prolonged treatment. In addition, if a greater proportion of patients are successfully treated with headgear because of improved compliance, fewer patients will need alternate treatments such as tooth extractions or jaw surgery. The proposed device uses a low-energy consumption, battery-powered microprocessor and sensors to assess the use of the orthodontic headgear. The project will develop a miniaturized version of the prototype that can be used in clinical orthodontics.